FRIDAY, Jan. 30, 2015 (HealthDay News) -- Humidity played a role in the evolution of languages, a new study suggests.

Languages with a wide range of tones are more common in areas of the world with high levels of humidity, while languages with a narrower range of tones are more common in less humid regions, the researchers explained.

"In relatively dry central Europe, no tonal languages have developed like those found in the Tropics, subtropical Asia and central Africa," said the authors of the study recently published in the Proceedings of the National Academy of Sciences.

The vocal folds in the larynx need a humid environment to produce a wide range of tonal pitch, which is why languages with wider tonal pitch are less common in less humid regions, they noted.

Tonal pitch plays an important role in all languages, but more so in some than in others, the researchers said.

English or German are still understandable even if all words are evenly intoned by a robot. However, the pitch tone can completely change the meaning of a word in Mandarin Chinese, they said. For example, "Ma" with a level pitch means "mother," while "ma" with a falling then rising pitch means "horse."

"Only those who hit the tone pitch correctly can express themselves in tonal languages," Sean Roberts, a scientist at the Max Planck Institute for Psycholinguistics in Nijmegen, Germany, said in an institute news release.

The researchers studied the link between humidity and tone pitch in more than 3,750 languages.

"If the UK had been a humid jungle, English may also have developed into a tonal language," Roberts said.